Mobile experiences are enriched by applications that support offline data access. Decentralized databases, file systems, storage systems, and email applications support disconnected operation to provide better mobility and availability. With the increasing use of mobile devices, such as laptops, tablets, and smart phones, a use should have access to data despite being offline.
However, support for such offline operation is at odds with security when the user is not trusted. An offline untrusted user (in full control of the user device) could perform arbitrary actions on whatever data was available and subsequently lie about it. This tension between mobility and security limits the use of disconnected operation in many potentially useful scenarios.